Contact lenses made of copolymers of polysiloxane methacrylates, alkyl acrylates or methacrylates or itaconates, hydrophilic monomers such as N-vinylpyrrolidone, hydroxyethyl methacrylate, (meth)acrylamide, diacetone acrylamide and, if appropriate, monomers which have a crosslinking effect, such as, for example, ethylene glycol dimethacrylate, are known (U.S. Pat. No. 3,808,178, U.S. Pat. No. 4,216,303, DE-A 2,363,627, WO 83/017,777, P. Rosenthal, CONTACT LENS FORUM; August 1982, pp. 47-57 and T. R. Williams, M. D. Nave, Polym. Mater. Sci. Eng. 52, pp. 279-283 (1985)). However, the poor surface wettability of the contact lenses is a disadvantage. Attempts are made to compensate for this disadvantage by subsequent hydrophilization of the surface, for example, by corona discharge or plasma treatment. However, the hydrophilization layer is not stable for long periods. After relatively long wear periods, the contact lenses losse their wettability land thus their compatibility.